Now as regards the Old Testament, my view is that God included it to show how one particular people filled out the meaning of the ten commandments in their culture. In his "But I say unto you" sayings in the Sermon on the Mount, Jesus obviously pointed out in six cases how they got it badly wrong.
In Acts 10 and 11 the Lord also had to correct their idea that the kosher food laws must apply to all people. In Acts 15 he had to correct the idea that circumcision was necessary for salvation. The letter to Philemon is Paul's revolutionary overturning the OT interpretation of laws about slavery. And in his 1 Corinthians 7:1-16, which Paul could only have got directly or indirectly from Jesus, there is a very radical overturning of patriarchal ideas of marriage.
That means that we cannot just quote verses from here and there on the assumption that they infallibly apply to us. What we have to ask is what God had in mind in His history (His Story) book from the beginning to the end ? In other words we have to compare Scripture with Scripture.
I am not sure if that answers the question. I would happily give more
examples if necessary. And I always welcome counter-examples - I learn
by offering a model, and then letting others show me the weaknesses.